Rane SM 82 User manual

SM 82
STEREO LINE MIXER
1 2
SM 82
SEND
BAL
SEND
BAL
3
SEND
BAL
4
SEND
BAL
5
SEND
BAL
6
SEND
BAL
7
SEND
BAL
8
RETURN OUTPUT
SEND
BAL BAL BAL
OL OL OL OL OL OL OL OL OL OL
LEVEL LEVELPOWER LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
10 10 10 10 10 10 10 10 10 10
0
5
10
STEREO
MIXER
R
C
L
0 5
10
R
C
L
0 5
10
R
C
L
0 5
10
R
C
L
0 5
10
R
C
L
0 5
10
R
C
L
0 5
10
R
C
L
0 5
10
R
C
L
R
C
L
R
C
L

108386
IMPORTANT SAFETY INSTRUCTIONS
For the continued safety of yourself and others we recommend that you read the following
safety and installation instructions. Keep this document in a safe location for future reference.
Please heed all warnings and follow all instructions.
Do not use this equipment in a location where it might become wet. Clean only with a damp
cloth.
is equipment may be installed in an industry standard equipment rack. We recommend that
all mounting holes be used, providing the best physical support. e equipment may be used as
a table top device, although stacking of the equipment is dangerous and not recommended.
Do not directly block any of the ventilation openings. If rackmounting, please provide adequate
ventilation. Equipment may be located directly above or below this unit, but note that some
equipment (like large power amplifiers) may cause an unacceptable amount of hum or may
generate too much heat and degrade the performance of this equipment.
Protect the power cord and plug from damage caused by being walked on or pinched. Protect
the line cord, where it exits the unit, from excessive strain. Only use attachments and acces-
sories specified by Rane.
Unplug this equipment during lightning storms or when unused for long periods of time.
Refer all servicing to qualified service personnel. Servicing is required when the apparatus has
been damaged in any way, such as power supply cord or plug damage, spilled liquid, fallen
objects into an opened chassis, exposure to rain or moisture, a dropped unit, or abnormal
operation.

Manual-1
OPERATORS MANUAL SM 82
STEREO MIXER
QUICK START
No one likes to read manuals. Everyone likes to just start pushing buttons and turning knobs until the desired results magically
emerge. at’s usually OK, and with a very few exceptions, damage is unlikely to result from such procedures with the SM 82.
is product is quite obvious: Input LEVEL controls make Inputs louder or not, the stereo SENDs make things happen at the
LOOP SEND outputs, and so on. No real magic there. You should be aware, however, that if you want to connect a mono source to
the SM 82, use only the LEFT Input of a channel so that the mono source will drive both the Left and the Right channels.
Set the levels of the mixer so that the red lights stay off. If they come on, you are overdoing it and distortion will result.
Never connect anything except an RS 1 or other approved Rane AC power supply to the thing that looks like a telephone
jack on the rear of the SM 82. is is an AC input and requires some special attention if you do not have an operational power sup-
ply exactly like the one that was originally packed with your unit. See the full explanation of the power supply requirements on page
Manual-3..
SM 82 CONNECTION
When connecting the SM 82 to other components in your
system for the first time, leave the power supply for last. is will
give you a chance to make mistakes and correct them before any
damage is done to your fragile speakers and ears.
INPUTS
e SM 82’s Inputs are unbalanced. is means that stan-
dard ¼" connectors on the ends of any good quality cable will
work well between your signal sources, signal processing and
amplification. For best rejection of nasty things like hum and
RF, keep input cables under 10 feet (3 meters) in length.
Most sources give you the choice of stereo or mono output.
e mixer gives you the same choice. You will note that nomen-
clature has been placed beneath the input jacks indicating which
is RIGHT and which is LEFT (MONO). If a source is plugged
only into the Left jack and not into the Right, both Right and
Left channels will be fed with the Left Input. is allows the use
of either stereo or mono sources.
OUTPUTS
e SM 82 offers balanced main outputs only. is means
that you may use them as either balanced or unbalanced, the
choice being made by the way the connectors are wired. It’s a
good idea to always use a TRS or stereo connector in the outputs
no matter which mode you are using. If a “mono” connector
is used, inserting it into the output will short the ring (–) to
ground and could conceivably cause a small amount of distortion
to be placed on the tip (+). While this is not destructive, it may
be significant enough to be audible. Balancing therefore requires
that both tip (+) and ring (–) be wired to the following device.
Unbalanced requires only tip and sleeve connected, leaving the
unused ring open.
EFFECTS DEVICES
External devices which might be used could be either mono
in and out, while some may be mono in and stereo out, while
still others may be stereo on both ends. e SM 82 easily ac-
commodates all of these varieties. If your effect is mono on both
ends, connect its input to the SM 82 LEFT LOOP SEND and
the effect’s output to the SM 82 LEFT LOOP RETURN. is
configuration will sum Right and Left Loop Outputs to the
mono effect input and will sum the mono effect output to the
Left and Right Input buses. A mono-in stereo-out device would
connect to the loop outputs in the same way; however the stereo
outputs connect to the respective LEFT and RIGHT LOOP
RETURNS.
EXPANDING
Connecting two or more SM 82s together to achieve more
than eight stereo Inputs requires that a stereo cable (tip, ring,
sleeve) be connected between the MAIN EXPAND OUTPUT
of the first mixer and the MAIN EXPAND INPUT of the
second. All 32 inputs will then appear at the main OUTPUT of
mixer number two. Only the first sixteen Inputs will be available
at the main Outputs of mixer number one. Should you wish to
have all Loop buses tied, connect the LOOP SENDS of mixer
one to the LOOP EXPAND INPUT of mixer two. All sixteen
stereo sends will then become active at the LOOP SENDS of the
second mixer.
WEAR PARTS: is product contains no wear parts.
1 2
SM 82
SEND BAL SEND BAL
3
SEND BAL
4
SEND BAL
5
SEND BAL
6
SEND BAL
7
SEND BAL
8RETURN OUTPUT
SEND BAL BAL BAL
OL OL OL OL OL OL OL OL OL OL
LEVEL LEVELPOWER LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
10 10 10 10 10 10 10 10 10 10
0
5
10
STEREO
MIXER
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
R
C
L
R
C
L

Manual-2
FRONT PANEL DESCRIPTION
1 POWER switch: Depress the upper portion of this switch to turn the unit on (with power supply plugged in); depress the lower
portion to turn the unit off. Depressing the center portion of the switch causes acute indecision stress to the switch’s personality
profile, which in turn depresses it. To alleviate this condition, the switch must be “turned on”, so to speak.
2 Input LEVEL control: is a rotary stereo attenuator that adjusts the amount of both Left and Right signals applied to the Input.
Its output is routed to the main summing amplifier for mixing with all other Inputs. e unity gain position of this control is
located at “7.5.”
3 Input OVERLOAD indicator: glows red whenever the Input’s output exceeds a level 4 dB below clipping, letting you know it’s a
good idea to turn this Input down a bit.
4 Input BALANCE control: In its center detent, Left and Right signals to each channel are allowed to pass at their original rela-
tive levels, therefore preserving the stereo image from instrument connected to the Inputs. When the control is moved vertically
toward the “L” position, the Right channel level is decreased while the Left channel level is maintained. e opposite occurs if the
control is moved from the detent down toward the “R”. When a mono input is used (no plug in the RIGHT Input jack), the BAL
control becomes a PAN control, panning the mono signal from the Left to Right channels.
5 Input SEND Level control: determines the amount of Post-Fade stereo input is fed to the auxiliary buses. Each Input’s stereo
SEND is summed on this bus and is available at the respective LEFT and RIGHT LOOP SENDS on the rear of the mixer.
6 RETURN LEVEL control: is a rotary stereo attenuator that controls the amount of Return which is to be added to the Main
Output. e unity gain position of this control is located at “7.5."
7 RETURN OVERLOAD indicator: glows red whenever the return levels exceed a level of 4 dB below clipping.
8 RETURN BALANCE control: is a vertical slider that controls the effect or source connected to the LOOP RETURN in the
same way the Input BALANCE controls work (see 4 above).
9 OUTPUT LEVEL control: is a rotary stereo attenuator that controls the final signal Level at the main OUTPUT jacks. e
unity gain position of this control is located at “7.5".
0 OUTPUT OVERLOAD indicator: glows red any time the output level exceeds 4 dB below clipping.
q OUTPUT BALANCE control: is a vertical slider that operates in the same fashion as the BALANCE control described in item
4 above. It however, determines the relative levels of the LEFT and RIGHT main OUTPUTS only.
1 2
SM 82
SEND BAL SEND BAL
3
SEND BAL
4
SEND BAL
5
SEND BAL
6
SEND BAL
7
SEND BAL
8RETURN OUTPUT
SEND BAL BAL BAL
OL OL OL OL OL OL OL OL OL OL
LEVEL LEVELPOWER LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL LEVEL
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
0
2
4
8
6
10 10 10 10 10 10 10 10 10 10
0
5
10
STEREO
MIXER
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
0
5
10
R
C
L
R
C
L
R
C
L
5 2
1 4 3
9 6
11 10 8 7

Manual-3
REAR PANEL DESCRIPTION
1 Main OUTPUT: ese balanced Tip-Ring-Sleeve jacks are used to connect the main Outputs of the SM 82 to a power amplifier
or to additional signal processing. As is the standard with all Rane balanced outputs using ¼" TRS jacks, the Tip is (+), the Ring
is (–) and the Sleeve is ground.
2 MAIN EXPAND OUTPUT: is ¼" TRS stereo (Tip = left, Ring = right) Output jack connects one SM 82 to another for the
purpose of expanding the number of Inputs available in the system. Only a stereo plug and cord should be used. To do otherwise
will cause loss of Right channel signal and possibly distortion to the Left channel. is Output also serves as a fixed pre-fader level
useful as tape outputs or other applications.
3 LOOP RETURN: ese ¼" aux returns may connect the output of a reverb or other effect unit to the Loop bus of the
SM 82. If no effect is used, they can be used as a ninth stereo Input to the mixer in addition to those described in 5.
As with the other stereo Inputs, mono signal may be connected to the LEFT input to obtain two channel mono operation.
4 LOOP SEND: is pair of ¼" jacks may drive an effect or similar device which is to be returned to item 3 above.
If a mono device is used, both the Left and Right Send channels of the SM 82 are summed together and presented at the LEFT
Output if nothing is inserted in the RIGHT Output.
5 Channel Input jacks: consist of Eight pairs of unbalanced ¼" tip-sleeve jacks, used to connect any line-level signal source to the
SM 82. As indicated, only the LEFT is to be used if the Input is mono and should therefore appear in both Left and Right chan-
nels, depending on the position of the front panel BALANCE control which is now effectively a PAN.
6 MAIN EXPAND INPUT: A ¼" TRS stereo Input jack may link two or more SM 82s together. e Left input is on the Tip,
Right on the Ring and the Sleeve is ground. is may also be used to sum any fixed-level stereo signal into the Main Outputs,
producing a tenth stereo Input when added with 5 and 3. As in 2 above, use only a stereo TRS cable.
7 LOOP EXPAND INPUT: Another ¼" TRS stereo Input, expands the stereo Loop buses of two SM 82s similar to the MAIN
EXPAND OUTPUT in 2. A stereo Tip-Ring-Sleeve cable must be used for this application. Connect the LEFT and RIGHT
LOOP SENDS (4) of the first unit to the LOOP EXPAND IN of the second unit. (Tip = left; Ring = right.)
8 Remote POWER supply input: Use only an RS 1 or other remote AC power supply approved by Rane. e SM 82 is supplied from
the factory with a remote power supply suitable for connection to this input jack. e power requirements of the SM 82 call for an
18-24 volt AC center-tapped transformer only. It is not a telephone jack. Using any other type of supply may damage the mixer and
will void the warranty (which at two years parts and labor is worth safeguarding).
9 Chassis ground point: A #6-32 screw is provided for chassis grounding purposes. See the note below for details.
CHASSIS GROUNDING
If after hooking up your system it exhibits excessive hum or buzzing, there is an incompatibility in the grounding configuration
between units somewhere. Your mission is to discover how your particular system wants to be grounded. Here are some things to try:
1. Try combinations of lifting grounds on units that are supplied with ground lift switches or links.
2. If your equipment is in a rack, verify that all chassis are tied to a good earth ground, either through the line cord grounding pin or
the rack screws to another grounded chassis.
3. Units with outboard power supplies, such as the SM 82, do not ground the chassis through the line cord. Make sure that these
units are grounded either to -another chassis which is earth grounded, or directly to the grounding screw on an AC outlet cover by
means of a wire connected to a screw on the chassis with a star washer to guarantee proper contact.
Please refer to the RaneNote, “Sound System Interconnection” (supplied in this manual and available separately) for further infor-
mation on system grounding.
MADE IN U.S.A. ALL INPUTS ARE UNBALANCED RANE CORP.
RING=R
TIP=L
RING=R
TIP=L
POWER
300mA
SM 82
8
LEFT RIGHT LEFT RIGHT LEFT RIGHT LEFT RIGHT
EXPAND
MAIN
(MONO)
OUTPUT
(MONO) (MONO)
7
LEFT RIGHT
(MONO)
6
LEFT RIGHT
(MONO)
5
LEFT RIGHT
(MONO)
4
LEFT RIGHT
(MONO)
3
LEFT RIGHT
(MONO)
2
LEFT RIGHT
(MONO)
1
LEFT RIGHT
(MONO)
LOOP RETURN
UNBALANCED
OUTPUT
BALANCED
LOOP SEND
UNBALANCED
MAIN LOOP
EXPAND
EXPAND
INPUT
CLASS 2 EQUIPMENT
INPUT
ACN 001 345 482
1 3 4 52 6 7 8
9

Manual-4
LEFT
(MONO)
INPUT
CHANNEL 1
+6 dB
BALANCE
INPUT
RIGHT
LEFT
(MONO)
INPUT
RIGHT
RFI
FILTER
FILTER
RFI
INPUT
LEVEL
+6 dB
INPUT
OVERLOAD
OL
SENSE
CH 2
LEVEL
SEND
RIGHT MAIN
RIGHT SEND
LEFT MAIN
LEFT SEND
R
R
L
L
L
LR
R
CH 3
L
LR
R
CH 4
L
LR
R
CH 5
L
LR
R
CH 6
L
LR
R
CH 7
L
LR
R
CH 8
0 dB
0 dB
SUMMING
AMPLIFIERS
DRIVERS
BALANCED
BALANCED
DRIVERS
OUTPUT
BALANCE
AMPLIFIERS
SUMMING
0 dB
0 dB
+L+R
LOOP
SENDS
RIGHT
LEFT
OUT
EXPAND
MAIN
RING
TIP
RIGHT
LEFT
+6 dB
+6 dB
LEVEL
OUTPUT
SENSE
OL
OVERLOAD
OUTPUT
LEFT
RIGHT
MAIN
OUTPUTS
SENSE
OL
OVERLOAD
RECEIVE
+6 dB
LEVEL
RECEIVE
RFI
FILTER
FILTER
RFI
RIGHT
INPUT
RECEIVE
BALANCE
+6 dB
RETURNS
INPUT
(MONO)
LEFT
LOOP
LEFT
RIGHT
TIP
RING
MAIN
EXPAND
INPUT
INPUT
EXPAND
LOOP
RING
TIP
RIGHT
LEFT
OPERATING INSTRUCTIONS
CIRCUIT DESCRIPTION
Learning to operate the SM 82 might be a bit easier if you
glance at the Block Diagram below. All eight stereo Inputs
operate in exactly the same way. Signal applied to the Inputs is
acted on by a radio interference filter (we have assumed that local
broadcasts should not be a part of your music) and is then routed
to a stereo LEVEL control. If you are using a mono source, con-
nect it only to the LEFT Input to send this mono signal to both
the Left and Right sides of the input circuitry. e output of the
Level control sections is applied to a unity gain buffer to prevent
the LEVEL control from adversely interacting with downstream
circuitry. e Input overload sensor monitors here to alert the
user via LED to any possible Input overload conditions. Left and
Right audio is then subjected to the channel BALance control to
allow the user to place the stereo image of the source as desired
to the Left and Right Outputs. If a mono input is present, the
BALance control becomes a PAN control. After the BALance
control has done its job, a stereo SEND LEVEL control adjusts
the amount of each Input routed to the Loop Output.
All eight stereo Inputs are simultaneously adjusted for stereo
placement by the OUTPUT BALance control. e resultant sig-
nal is added together and fed to the OUTPUT LEVEL control,
which has it’s own Overload indicator. e main Outputs are
fully actively balanced, allowing the use of correctly wired long
cables.
EFFECTS LOOP
e LOOP SENDS receive their audio from the Send bus
which is the sum of all the Inputs as determined by the Input
SEND controls. is Output may be used to drive a stereo
effects processor. e output of the effect device is returned to
the SM 82 through the LOOP RETURNS. e level of the
returned effect is determined by the RETURN LEVEL control
on the front panel. e return section also provides a BALance
control for image placement.
BALANCE CONTROLS
ese do not increase the level of either Left or Right signal.
As the controls are moved toward one channel, the level of the
other channel is only reduced.
HIGH NOISE IMMUNITY
One of the most unusual features of the SM 82 is its inher-
ent immunity from noise. All eight of the stereo inputs may be
turned all the way up without increasing the internal noise of the
mixer. is is critical due to the wide variation in output levels
found in musical instruments and tape devices. A fairly low-level
synthesizer may be combined in the same system with a high
level unit without any undesirable side-effects. e SM 82 elimi-
nates the concerns normally associated with mixing so-called -l0
dBV units with +4 dBu types.
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5098 USA TEL [phone] FAX [phone] WEB www.rane.com
107271
Block Diagram